Field of the Invention
The present invention relates to a wear amount detection device for an automobile tire that detects a wear state of a tire of an automobile during running, and relates to a technique to issue a warning regarding safety to a driver or notify the driver of arrival of a time to replace a tire.
Description of Related Art
Patent Document 1 discloses a device in which a conductive rubber resistor is embedded in a tread element, a signal of a change in resistance value caused by the resistor being removed due to wear is transmitted, and a wear state is determined through processing of the received detection signal.
Patent Document 2 discloses a method in which block rows of a tread element is formed to have a cross-sectional shape in which the number of blocks in a circumferential direction changes along with wear of a tire, vibration of a member disposed below a spring is detected, and the frequency of a rotation synchronous component is analyzed, thereby estimating a level of wear.
Patent Document 3 discloses a method in which recesses having different depths are formed so as to be arranged periodically along the circumferential direction of a tire, a vibration component caused due to the recesses is extracted from a vibration signal of a member below a spring, and a wear state is estimated on the basis of the magnitude of the vibration component.
Patent Document 4 discloses a high-resolution rotation detection device that is mounted on a wheel bearing of an automobile and provided with a function to multiply a signal.
Patent Document 5 discloses a rotation detection device that is mounted on a wheel bearing of an automobile and capable of detecting an absolute angle.
Patent Document 6 discloses a method for estimating a slip ratio or the like from a rotation sensor signal of a tire, and also discloses a method for averaging and detecting rotation synchronous components from a rotation signal of a tire over several rotations.